1 files changed, 418 insertions, 0 deletions
diff --git a/lib/crypto_backend/crypto_kernel.c b/lib/crypto_backend/crypto_kernel.c
new file mode 100644
index 0000000..2881ed4
--- /dev/null
+++ b/lib/crypto_backend/crypto_kernel.c
@@ -0,0 +1,418 @@
+/*
+ * Linux kernel userspace API crypto backend implementation
+ *
+ * Copyright (C) 2010-2021 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2010-2021 Milan Broz
+ *
+ * This file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This file is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <sys/socket.h>
+#include <sys/utsname.h>
+#include <linux/if_alg.h>
+#include "crypto_backend_internal.h"
+
+/* FIXME: remove later */
+#ifndef AF_ALG
+#define AF_ALG 38
+#endif
+#ifndef SOL_ALG
+#define SOL_ALG 279
+#endif
+
+static int crypto_backend_initialised = 0;
+static char version[256];
+
+struct hash_alg {
+	const char *name;
+	const char *kernel_name;
+	int length;
+	unsigned int block_length;
+};
+
+static struct hash_alg hash_algs[] = {
+	{ "sha1",      "sha1",        20,  64 },
+	{ "sha224",    "sha224",      28,  64 },
+	{ "sha256",    "sha256",      32,  64 },
+	{ "sha384",    "sha384",      48, 128 },
+	{ "sha512",    "sha512",      64, 128 },
+	{ "ripemd160", "rmd160",      20,  64 },
+	{ "whirlpool", "wp512",       64,  64 },
+	{ "sha3-224",  "sha3-224",    28, 144 },
+	{ "sha3-256",  "sha3-256",    32, 136 },
+	{ "sha3-384",  "sha3-384",    48, 104 },
+	{ "sha3-512",  "sha3-512",    64,  72 },
+	{ "stribog256","streebog256", 32,  64 },
+	{ "stribog512","streebog512", 64,  64 },
+	{ "sm3",       "sm3",         32,  64 },
+	{ "blake2b-160","blake2b-160",20, 128 },
+	{ "blake2b-256","blake2b-256",32, 128 },
+	{ "blake2b-384","blake2b-384",48, 128 },
+	{ "blake2b-512","blake2b-512",64, 128 },
+	{ "blake2s-128","blake2s-128",16,  64 },
+	{ "blake2s-160","blake2s-160",20,  64 },
+	{ "blake2s-224","blake2s-224",28,  64 },
+	{ "blake2s-256","blake2s-256",32,  64 },
+	{ NULL,        NULL,           0,   0 }
+};
+
+struct crypt_hash {
+	int tfmfd;
+	int opfd;
+	int hash_len;
+};
+
+struct crypt_hmac {
+	int tfmfd;
+	int opfd;
+	int hash_len;
+};
+
+struct crypt_cipher {
+	struct crypt_cipher_kernel ck;
+};
+
+static int crypt_kernel_socket_init(struct sockaddr_alg *sa, int *tfmfd, int *opfd,
+				    const void *key, size_t key_length)
+{
+	*tfmfd = socket(AF_ALG, SOCK_SEQPACKET, 0);
+	if (*tfmfd < 0)
+		return -ENOTSUP;
+
+	if (bind(*tfmfd, (struct sockaddr *)sa, sizeof(*sa)) < 0) {
+		close(*tfmfd);
+		*tfmfd = -1;
+		return -ENOENT;
+	}
+
+	if (key && setsockopt(*tfmfd, SOL_ALG, ALG_SET_KEY, key, key_length) < 0) {
+		close(*tfmfd);
+		*tfmfd = -1;
+		return -EINVAL;
+	}
+
+	*opfd = accept(*tfmfd, NULL, 0);
+	if (*opfd < 0) {
+		close(*tfmfd);
+		*tfmfd = -1;
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+int crypt_backend_init(void)
+{
+	struct utsname uts;
+	struct sockaddr_alg sa = {
+		.salg_family = AF_ALG,
+		.salg_type = "hash",
+		.salg_name = "sha256",
+	};
+	int r, tfmfd = -1, opfd = -1;
+
+	if (crypto_backend_initialised)
+		return 0;
+
+	if (uname(&uts) == -1 || strcmp(uts.sysname, "Linux"))
+		return -EINVAL;
+
+	r = snprintf(version, sizeof(version), "%s %s kernel cryptoAPI",
+		uts.sysname, uts.release);
+	if (r < 0 || (size_t)r >= sizeof(version))
+		return -EINVAL;
+
+	if (crypt_kernel_socket_init(&sa, &tfmfd, &opfd, NULL, 0) < 0)
+		return -EINVAL;
+
+	close(tfmfd);
+	close(opfd);
+
+	crypto_backend_initialised = 1;
+	return 0;
+}
+
+void crypt_backend_destroy(void)
+{
+	crypto_backend_initialised = 0;
+}
+
+uint32_t crypt_backend_flags(void)
+{
+	return CRYPT_BACKEND_KERNEL;
+}
+
+const char *crypt_backend_version(void)
+{
+	return crypto_backend_initialised ? version : "";
+}
+
+static struct hash_alg *_get_alg(const char *name)
+{
+	int i = 0;
+
+	while (name && hash_algs[i].name) {
+		if (!strcmp(name, hash_algs[i].name))
+			return &hash_algs[i];
+		i++;
+	}
+	return NULL;
+}
+
+/* HASH */
+int crypt_hash_size(const char *name)
+{
+	struct hash_alg *ha = _get_alg(name);
+
+	return ha ? ha->length : -EINVAL;
+}
+
+int crypt_hash_init(struct crypt_hash **ctx, const char *name)
+{
+	struct crypt_hash *h;
+	struct hash_alg *ha;
+	struct sockaddr_alg sa = {
+		.salg_family = AF_ALG,
+		.salg_type = "hash",
+	};
+
+	h = malloc(sizeof(*h));
+	if (!h)
+		return -ENOMEM;
+
+	ha = _get_alg(name);
+	if (!ha) {
+		free(h);
+		return -EINVAL;
+	}
+	h->hash_len = ha->length;
+
+	strncpy((char *)sa.salg_name, ha->kernel_name, sizeof(sa.salg_name)-1);
+
+	if (crypt_kernel_socket_init(&sa, &h->tfmfd, &h->opfd, NULL, 0) < 0) {
+		free(h);
+		return -EINVAL;
+	}
+
+	*ctx = h;
+	return 0;
+}
+
+int crypt_hash_write(struct crypt_hash *ctx, const char *buffer, size_t length)
+{
+	ssize_t r;
+
+	r = send(ctx->opfd, buffer, length, MSG_MORE);
+	if (r < 0 || (size_t)r < length)
+		return -EIO;
+
+	return 0;
+}
+
+int crypt_hash_final(struct crypt_hash *ctx, char *buffer, size_t length)
+{
+	ssize_t r;
+
+	if (length > (size_t)ctx->hash_len)
+		return -EINVAL;
+
+	r = read(ctx->opfd, buffer, length);
+	if (r < 0)
+		return -EIO;
+
+	return 0;
+}
+
+void crypt_hash_destroy(struct crypt_hash *ctx)
+{
+	if (ctx->tfmfd >= 0)
+		close(ctx->tfmfd);
+	if (ctx->opfd >= 0)
+		close(ctx->opfd);
+	memset(ctx, 0, sizeof(*ctx));
+	free(ctx);
+}
+
+/* HMAC */
+int crypt_hmac_size(const char *name)
+{
+	return crypt_hash_size(name);
+}
+
+int crypt_hmac_init(struct crypt_hmac **ctx, const char *name,
+		    const void *key, size_t key_length)
+{
+	struct crypt_hmac *h;
+	struct hash_alg *ha;
+	struct sockaddr_alg sa = {
+		.salg_family = AF_ALG,
+		.salg_type = "hash",
+	};
+	int r;
+
+	h = malloc(sizeof(*h));
+	if (!h)
+		return -ENOMEM;
+
+	ha = _get_alg(name);
+	if (!ha) {
+		free(h);
+		return -EINVAL;
+	}
+	h->hash_len = ha->length;
+
+	r = snprintf((char *)sa.salg_name, sizeof(sa.salg_name),
+		 "hmac(%s)", ha->kernel_name);
+	if (r < 0 || (size_t)r >= sizeof(sa.salg_name)) {
+		free(h);
+		return -EINVAL;
+	}
+
+	if (crypt_kernel_socket_init(&sa, &h->tfmfd, &h->opfd, key, key_length) < 0) {
+		free(h);
+		return -EINVAL;
+	}
+
+	*ctx = h;
+	return 0;
+}
+
+int crypt_hmac_write(struct crypt_hmac *ctx, const char *buffer, size_t length)
+{
+	ssize_t r;
+
+	r = send(ctx->opfd, buffer, length, MSG_MORE);
+	if (r < 0 || (size_t)r < length)
+		return -EIO;
+
+	return 0;
+}
+
+int crypt_hmac_final(struct crypt_hmac *ctx, char *buffer, size_t length)
+{
+	ssize_t r;
+
+	if (length > (size_t)ctx->hash_len)
+		return -EINVAL;
+
+	r = read(ctx->opfd, buffer, length);
+	if (r < 0)
+		return -EIO;
+
+	return 0;
+}
+
+void crypt_hmac_destroy(struct crypt_hmac *ctx)
+{
+	if (ctx->tfmfd >= 0)
+		close(ctx->tfmfd);
+	if (ctx->opfd >= 0)
+		close(ctx->opfd);
+	memset(ctx, 0, sizeof(*ctx));
+	free(ctx);
+}
+
+/* RNG - N/A */
+int crypt_backend_rng(char *buffer, size_t length, int quality, int fips)
+{
+	return -EINVAL;
+}
+
+/* PBKDF */
+int crypt_pbkdf(const char *kdf, const char *hash,
+		const char *password, size_t password_length,
+		const char *salt, size_t salt_length,
+		char *key, size_t key_length,
+		uint32_t iterations, uint32_t memory, uint32_t parallel)
+{
+	struct hash_alg *ha;
+
+	if (!kdf)
+		return -EINVAL;
+
+	if (!strcmp(kdf, "pbkdf2")) {
+		ha = _get_alg(hash);
+		if (!ha)
+			return -EINVAL;
+
+		return pkcs5_pbkdf2(hash, password, password_length, salt, salt_length,
+				    iterations, key_length, key, ha->block_length);
+	} else if (!strncmp(kdf, "argon2", 6)) {
+		return argon2(kdf, password, password_length, salt, salt_length,
+			      key, key_length, iterations, memory, parallel);
+	}
+
+	return -EINVAL;
+}
+
+/* Block ciphers */
+int crypt_cipher_init(struct crypt_cipher **ctx, const char *name,
+		    const char *mode, const void *key, size_t key_length)
+{
+	struct crypt_cipher *h;
+	int r;
+
+	h = malloc(sizeof(*h));
+	if (!h)
+		return -ENOMEM;
+
+	r = crypt_cipher_init_kernel(&h->ck, name, mode, key, key_length);
+	if (r < 0) {
+		free(h);
+		return r;
+	}
+
+	*ctx = h;
+	return 0;
+}
+
+void crypt_cipher_destroy(struct crypt_cipher *ctx)
+{
+	crypt_cipher_destroy_kernel(&ctx->ck);
+	free(ctx);
+}
+
+int crypt_cipher_encrypt(struct crypt_cipher *ctx,
+			 const char *in, char *out, size_t length,
+			 const char *iv, size_t iv_length)
+{
+	return crypt_cipher_encrypt_kernel(&ctx->ck, in, out, length, iv, iv_length);
+}
+
+int crypt_cipher_decrypt(struct crypt_cipher *ctx,
+			 const char *in, char *out, size_t length,
+			 const char *iv, size_t iv_length)
+{
+	return crypt_cipher_decrypt_kernel(&ctx->ck, in, out, length, iv, iv_length);
+}
+
+bool crypt_cipher_kernel_only(struct crypt_cipher *ctx)
+{
+	return true;
+}
+
+int crypt_bitlk_decrypt_key(const void *key, size_t key_length,
+			    const char *in, char *out, size_t length,
+			    const char *iv, size_t iv_length,
+			    const char *tag, size_t tag_length)
+{
+	return crypt_bitlk_decrypt_key_kernel(key, key_length, in, out, length,
+					      iv, iv_length, tag, tag_length);
+}